This invention relates to improved gasket assemblies, and particularly to improved oil pan gaskets, valve cover gaskets and the like for automotive use.
Oil pan gaskets, valve cover gaskets and the like are typically made of rubber, cork, and cork-rubber sheets or laminates. Such gaskets define openings through which fasteners, such as bolts, extend between the clamping surfaces. When the fasteners are torqued down, the gaskets are sometimes excessively compressed causing splitting, thereby resulting in the undesirable formation of leakage paths.
It has been suggested that stops be used to control the degree of compression permitted at the fastener holes. In one recent development, disclosed in U.S. Pat. No. 4,535,996, rigid stops are provided in fastener openings in a unitary, molded gasket. The stop members are secured to the core by a staking operation. Such stops limit compression of the gasket and also limit displacement of the elastomer adjacent the opening, thereby to avoid leakage problems resulting from excessive compression of the gasket.
It would be desirable to provide an improved means for limiting compression of gaskets in fastener apertures which did not require a staking operation to secure compression stoppers in place and which was easy to assemble.